The present invention relates generally to the field of emergency buoyancy systems for vessels and, more particularly, to an automatically deployed buoyancy system which senses hydrostatic pressure and, upon sensing a predetermined threshold of pressure, mixes two chemicals which form a gas, thereby filling buoyancy balloons or bladders to maintain the vessel afloat.
Every year, vessels are lost at sea. Pleasure vessels, both power and sail, are also all too commonly lost on rivers and lakes throughout the world. In small craft, the problem has been somewhat alleviated by the advent of new materials of construction, whereby the vessel itself is made of a flotation material, so that if the entire vessel is filled with water, then the craft does not sink. The problem remains, however, with larger vessels.
Many systems have been designed and installed to make ships and boats more seaworthy and to keep such craft afloat if they begin to take on water. Most commonly, ships use pumps of one sort or another to pump water from inside the hull to a discharge over the side. Such systems have been used successfully for generations, and have save many lives, so long as the capacity of the pumping system exceeds the rate at which water is entering the hull through a breach. Once the rate at which water is taken on outstrips the capacity of the pumps to pump it over, the vessel is doomed to sink.
Thus, there remains a need for a system to keep vessels afloat, even if emergency bilge pumps and the like cannot keep up with the rate at which water is taken on in a flooding situation. Such a system should provide buoyancy to the vessel by displacing sufficient water to keep the vessel afloat, either until help can arrive, repairs can be performed, or until the vessel can be brought to port.
Pure distilled water has a relative weight of 1 at a temperature of 4xc2x0 C., that is, 1 cm3 of water weighs 1 gram. Seawater is heavier than fresh water by 2.5-3% because of the greater amount of salts dissolved in it; its relative weight is 1.025. It may be concluded that a vessel weighs less in seawater than in fresh water. Relative weight is important for determining buoyancy. Thus, if sufficient volume of fresh water is displaced by a buoyancy system to maintain a vessel afloat, the system will also maintain the same vessel afloat in seawater. The present invention is directed to solving this long felt problem in the art.
The present invention provides an emergency buoyancy system mounted to a vessel that includes a depth sensor to sense a predetermined maximum depth, and an actuator actuated by the depth sensor. The actuator, upon actuation, opens a membrane between a pair of gas producing chemicals. The gas producing chemicals, preferably bicarbonate of soda and vinegar, mix together to produce carbon dioxide. The carbon dioxide fills a plurality of balloons, thereby providing buoyancy to the vessel to which the balloons are attached.
The buoyancy system preferably includes a large number of relatively small balloons anchored to the frames of the vessel. That way, if any balloon fails to inflate, or is damaged in some way so that it does not contribute to the buoyancy of the vessel, the remaining balloons will still float the vessel, and very little instability is introduced by the failure of one or even a small number of balloons.
The balloons are preferably anchored to the frames of the vessel, and no to the hull or any other portion of the ship which is not designed to withstand the upward force contributed by the balloons. The balloons are each relatively small, no more than a hundred cubic meters or so, but a large number is provided to provide more than enough buoyancy to float the vessel even if it is substantially damaged. In fact, the vessel can the separated into several sections and since the balloons are dispersed along the hull, each fragment of the vessel is floated by the present invention.
For example, a 10,000 ton ship weighs about 20 million pounds, or 9 million kilograms. The balloons of the present invention must displace about 9,000 cubic meters of water to provide the entire buoyancy to the ship, although that is the worst case scenario. If each small balloon displaces 100 cubic meters when fully inflated, then about 90 such balloons, or 45 on the starboard side and 45 on the port side are required. Each balloon will therefore be roughly 6 meters in diameter. To provide adequate margin for buoyancy, including some system failures, the present invention contemplates at least 100 such balloons on each side of a vessel of this size. Smaller vessel require smaller and fewer balloons. And, since the balloons are dispersed in an array along the hull of the ship, if the ship breaks up then each piece of the ship will have an adequate portion of the floatation system of this invention.
While the bicarbonate of soda and vinegar are preferred, other gas producing chemicals may be used. In any event, one of the gas producing chemicals is preferably a liquid, since the preferred embodiment relies on gravity to bring the liquid chemical into contact with the other gas producing chemical.